Limited-time Security Control Of Power Systems Under Cyber Attack

With the large-scale development of modern power system,the safety control has become an important and popular research topic.The feedback control system composed of actuators、sensors and observers,widely exists in the modern power system,and the data transmission between each part is carried out through the communication network.In an open communication environment,malicious network attacks invade the power system through communication networks and have adverse effects on the power and stability of the power system.In order to maintain the stability and scheduling of the power system,security control research mainly includes modeling under network attack scenarios and security control strategies for different network attacks.Currently,it has been widely applied in industrial production,transportation and medical fields.These two most common typical network attacks in the power system includes deception attack and denial of service(DoS)attack.Attackers break through network defense against the imperfection of information security,causing serious negative impact on the system and even causing to collapse.Based on this,this paper designs event-triggered and self-triggered controller for power systems with external interference in the presence of network attacks to reduce the frequency of outsourcing in network channels,enabling the system with good performance while saving communication resources.The research work of this article can be summarized as follows:The first part studies the issue of finite-time security control in power systems under periodic DoS attack and deception attack based on event-triggering mechanism.Firstly,under the ideal network environment,the dynamic model of the power system is established.Secondly,considering the periodic denial of service attack and deception attack on the system,a model-based event-triggered transmission mechanism is designed by dividing the time interval into non-denial of service attack intervals and denial of service attack intervals,and a new dynamic model is established,which includes deception attack and uncertainty of system parameters.To reduce the negative impact of mixed network attack on power system state information,the corresponding attack compensation strategy and the function related to the probability of deception attack are designed.Secondly,based on Lyapunov stability theory and singular value decomposition,the sufficient conditions for the stochastic finite-time stability of power system are verified,and greatly reducing the waste of communication resources.Finally,the linear matrix inequality technology is used to verify the superiority of the above event-triggered control strategy through the simulation of the power system.The second part studies the finite-time load frequency control of power systems under random DoS attack.Firstly,when the system is subjected to random denial of service attack,assuming that the attacker maliciously attack the power system in the form of probability,a dynamic model of the power system is established,which includes random denial of service attack and uncertainty of system parameters.Secondly,based on the integral inequality of the free weight matrix and the Wirtinger integral inequality,a load frequency control mechanism based on self-triggered control is proposed.Based on Lyapunov stability theory,the sufficient conditions for the stochastic finite-time stability of power dynamic system are established,verifing that the power system with H∞ performance enables the power system to maintain stable and secure operation under random denial of service attack,and improves the effectiveness of resource conservation.Finally,the linear matrix inequality technology is used to verify the superiority of the proposed scheme through the simulation of a power system example.